Phylum Porifera Grant, 1836 - sponges Class Demospongea Sollas, 1875 see Class Demospongiae Sollas, 1885 Subclass Tetractinomorpha Lévi, 1953 see Class Demospongiae Sollas, 1885 Order †Hadromerida Topsent, 1894 Family †Polysiphonidae Girty, 1909 Genus †Polysiphon Girty, 1908